Physical Biology of the Celltakes key cell biology experiments through a quantitative treatment to demonstrate how models can help refine our understanding and prediction of biological phenomena. The second edition upgrades to full color format and includes two new chapters on photosynthesis and pattern formation. Two new classes of special feature boxes called "Computational Explorations" and "Counters, Rulers, and Stopwatches" will increase the emphasis on computation as a complement to analytic calculation and describe the intriguing ways cells and humans have devised for counting and measuring distances and times. There are twice as many end-of-chapter problems and new modeling material will be offered online.